Core Data commands crash ViewController even after delete - swift

Question

I was trying to add autosaving to my Core Data-based app and there was a line of code I added to textDidChange in a CollectionViewItem:
theNote?.updateChangeCount(NSDocumentChangeType.ChangeDone)
That gave me a lot of errors, so I commented out the line. I then went in to delete the CocoaAppCD.storedata persistent store file to make it cleaner (I'm still in early dev stages so all that goes in my persistent store is random test materials).
Now, I'm finding, Core Data commands crash my ViewController. Specifically this function:
func createNewNotebook(folderURL: NSURL)
{
let currentNotebook = Notebook(entity: sv.noteType, insertIntoManagedObjectContext:sv.context)
currentNotebook.folderURLstring = folderURL.absoluteString
let noteSet = currentNotebook.mutableSetValueForKey("contains")
print(String(noteSet))
intakeFilesFromFolder(noteSet, currentFolderURL: folderURL)
}
(Notebook and NoteEntity are the two entity types in my Core Data model.) When either the currentNotebook.folder... or let noteSet... commands run, I get these errors in my console:
Brouillon.NoteEntity folderURLstring]: unrecognized selector sent to instance 0x6080000a3a20
2016-07-24 19:27:02.622 Brouillon[8006:361665] Failed to set (contentViewController) user defined inspected property on (NSWindow): -[Brouillon.NoteEntity folderURLstring]: unrecognized selector sent to instance 0x6080000a3a20
and the WindowController is empty with no view filling it (even though these same statements had worked before I added the now-commented-out line). But if I bypass this function so the Core Data statements don't run, the views load. I would have thought that if I had anything dirty left in the database, deleting the CocoaAppCD.storedata file should have fixed it (and I keep deleting that file after every run). But it seems like something in Core Data is still mucked up for me - any ideas?

Answer 1

I figured this out. The problem was I had declared the wrong entity type: my sv.noteType should have been sv.notebookType, since it was a Notebook rather than a NoteEntity. (The error would have been introduced when I was creating the class instantiated as sv, as a class to hold my otherwise-duplicated code.)